The present disclosure relates to a process and an apparatus for forming a platinum modified cathodic arc coating on a part, such as a turbine engine component.
The high temperature exposure of nickel-based superalloys in turbine engines continues to increase. Thus, alloys must continually be adapted to this high temperature combustion environment. Advanced thermal barrier coating systems (TBCs) provide a means to shelter the structural element, i.e turbine blade or vane, from the highest temperatures in the engine; however, oxidation of the metal surface below still takes place as the thermal barrier coating is oxygen transparent. Metallic bond coats are added to the metallic surface of the substrate to form a reaction product of thermally grown oxide (TGO) of alumina between the bond coat and the TBC topcoat. As superalloy technology advances, creep resistant higher refractory-containing superalloys become of interest; however, these alloys are prone to being incompatible with currently available bond coats. Secondary reaction zones (SRZs) typically form at the bond coat-superalloy interfaces in superalloy systems containing high amounts of rhenium and/or ruthenium and results in a loss of mechanical integrity of the material.